Chemistry paper 34 as level practical guess papers

[KatnissEver]

Does anyone have any idea as to what could come in chem paper 34. Please keep me updated . Thanks

 

[hassannouman]

Does anyone have any idea as to what could come in chem paper 34. Please keep me updated . Thanks

Yes, there will be 3 questions according to the trend now
Titration and Salt Analysis are confirmed, 3rd question might be about enthalpy change/ temperature change etc

 

[KatnissEver]

OKay thanks

 

[KatnissEver]

Just keep me updated if any info regarding what may come

 

[sarmad zubair]

bro i am solving practicals but can not differentiate between enthalpy change and temperature change questions? whts the difference i mean both are about temperature change!!!! plz help me!!!!

 

[KatnissEver]

They are basically the same thing. Well. Almost. I'm having trouble in titration calculations

 

[hassannouman]

bro i am solving practicals but can not differentiate between enthalpy change and temperature change questions? whts the difference i mean both are about temperature change!!!! plz help me!!!!

They are same, question be like You need to carry out an experiment to find out the enthalpy change of X, then you note initial / final temperatures and other measurements to do calculations later.

 

[hassannouman]

Don't forget to add only 3 drops of indicator in titration question

 

[Abdul Hanan]

can any one help me regarding titration
-do we include rough titration results in our table?
-what should be the difference between rough titrations and our 1st and 2nd titrations?

 

[Mathemagical]

I have finished the Chemistry Paper 33 on May 7, and I will share some information on the paper with all of you.

Question 1:
A normal titration question, but this time the indicator used was bromothymol blue, the first time I've seen it appear in a practical paper. I performed a rough titration, and for the following accurate titrations I titrated near to the end point and added a drop every 3 seconds to ensure I got a value which was as accurate as possible. It was around 22.10, and most of my fellow lab-mates got within 0.20cm3 of my titration. The calculations preceding that were standard questions, and I encountered no problems with them.

Question 2:
A heat loss question, we had to measure the temperature rise for different volumes of reagent and plot a graph. I drew 2 curves, one for an increase and the other for a decrease, and found the intercept. There was no need for a repetition in this question, and I found it quite satisfactory. It was followed by questions involving calculations and improvements to the method. Now for this part quite a lot of my friends had stated changes to the apparatus, but I doubt those answers would be accepted because the question had specified on the method. I suggested adding the reagent in 2cm3 graduations instead of 5cm3 to improve the value of the intercept.

Question 3:
Another typical qualitative analysis question. We had to heat compounds and test for gases, in this case ammonia. However, the last bit was a little tricky. It asked us to name a reagent to test if oxidation had occurred to the cation we identified. I used sodium hydroxide for it because the cation I had identified was Fe2+ and oxidation would mean that it turned into Fe3+, hence yielding a different result with sodium hydroxide (brown precipitate). However, no change occurred and I concluded that the cation had not been oxidised.

Overall I found the paper quite good and didn't feel any time constraints. Just read the instructions carefully, have a good breakfast, sleep well the day before and you're on your way to an A

P.S. If you have any further questions please leave a comment and I will get back to you as soon as possible.

 

[bubbles1997]

can any one help me regarding titration
-do we include rough titration results in our table?
-what should be the difference between rough titrations and our 1st and 2nd titrations?

For titrations, we will never add 'rough' titre in the table
Secondly, we will always have rough titre more. For example, the rough titre is 26cm^3. When we perform our first titration, we must have a value about 24cm^3 or 27cm^3. It decreases the chances of error

 

[KatnissEver]

Guys tomorrow is the paper. Does anyone have any idea as t what may come or the ions or anything

 

[hassannouman]

can any one help me regarding titration
-do we include rough titration results in our table?
-what should be the difference between rough titrations and our 1st and 2nd titrations?

In practicals , we always included the rough titre. Just mention rough in bracket and you can add the rough titre in your table.
For rough titre, just keep adding the volume (solution in burette) till the colour changes. Note down the volume, in 1st accurate titration stop 4-5cm3 before the rough value, then add drop by drop till colour changes.

 

[Abdul Hanan]

For titrations, we will never add 'rough' titre in the table
Secondly, we will always have rough titre more. For example, the rough titre is 26cm^3. When we perform our first titration, we must have a value about 24cm^3 or 27cm^3. It decreases the chances of error

In practicals , we always included the rough titre. Just mention rough in bracket and you can add the rough titre in your table.
For rough titre, just keep adding the volume (solution in burette) till the colour changes. Note down the volume, in 1st accurate titration stop 4-5cm3 before the rough value, then add drop by drop till colour changes.

That's helpful. Thanks